71M6543F Maxim, 71M6543F Datasheet - Page 17

• Manufacturer Part Number: 71M6543F
• Description: The 71M6543F/71M6543H are Teridian's 4th-generation polyphase metering system-on-chips (SoCs) with a 5MHz, 8051-compatible MPU core, low-power real-time clock (RTC) with digital temperature compensation, flash memory, and LCD driver
• Manufacturer: Maxim

For a polyphase configuration with neutral current sensing using shunt resistor current sensors and the
71M6xx3 isolated sensors, as shown in
differential input, to be connected to a local shunt (see
local shunt connected to the IADC0-IADC1 input is used to sense the Neutral current. The voltage
sensors (VADC8, VADC9 and VADC10) are also directly connected to the 71M6543 (see
the connection details) and are also routed though the multiplexer, as seen in
IADC2-IADC3, IADC4-IADC5 and IADC6-IADC7 current inputs are configured as remote sensor digital
interfaces and the corresponding samples are not routed through the multiplexer. For this configuration,
the multiplexer sequence is as shown in
For a polyphase configuration with optional neutral current sensing using Current Transformer (CTs)
sensors, as shown in
be connected to their corresponding CTs (see
IADC0-IADC1 current sensor input is optionally used to sense the Neutral current for anti-tampering
purposes. The voltage sensors (VADC8, VADC9 and VADC10) are directly connected to the 71M6543
(see
configuration and all sensors are routed though the multiplexer, as seen in
configuration, the multiplexer sequence is as shown in
The multiplexer sequence shown in
frame duration is 13 CK32 cycles (where CK32 = 32,768 Hz), therefore, the resulting sample rate is
32,768 Hz / 13 = 2,520.6 Hz. Note that
multiplexer, and does not show the currents that are copied directly into CE RAM from the remote
sensors (see
unused conversion slots shown are necessary to produce the desired 2,520.6 Hz sample rate.
The multiplexer sequence shown in
Since in this case all current sensors are locally connected to the 71M6543, all currents are routed
through the multiplexer, as seen in
cycles (where CK32 = 32,768 Hz), therefore, the resulting sample rate is 32,768 Hz / 15 = 2,184.5 Hz.
v1.2
Figure 27
MUX STATE
MUX_SYNC
Using settings for the I/O RAM Mnemonics listed in
those required by the corresponding CE code being used may result in undesirable side
effects and must not be selected by the MPU. Consult your local Teridian representative to
obtain the correct CE code and AFE / MUX settings corresponding to the application.
CROSS
Figure
CK32
MUX STATE
MUX_SYNC
for the voltage sensor connection details). No 71M6xx3 isolated sensors are used in this
CROSS
CK32
2), which are sampled during the second half of the multiplexer frame. The two
Figure
Figure 4: States in a Multiplexer Frame (MUX_DIV[3:0] = 6)
Figure 5: States in a Multiplexer Frame (MUX_DIV[3:0] = 7)
S
S
© 2008–2011 Teridian Semiconductor Corporation
3, all four current sensor inputs must be configured as a differential inputs, to
IA
0
IN
0
Figure
Figure 4
Figure 5
VA
Figure 4
1
Unused
Figure
Figure
1
3. For this multiplexer sequence, the frame duration is 15 CK32
MUX_DIV[3:0]
corresponds to the configuration shown in
corresponds to the CT configuration shown in
MUX_DIV[3:0]
Figure 29
2, the IADC0-IADC1 input must be configured as a
4.
Unused
only shows the currents that pass through the 71M6543
IB
2
Multiplexer Frame
2
Multiplexer Frame
Figure 30
Figure
for the differential CT connection details). The
VA
3
VB
= 6 Conversions
3
= 7 Conversions
71M6543F/H and 71M6543G/GH Data Sheet
5.
Table 1
for the shunt connection details). The
4
VB
4
IC
and
VC
5
Figure
Table 2
VC
Figure
5
Settle
S
3. For this
that do not match
2. Meanwhile, the
IN
Figure
6
Figure 27
Figure
Settle
2. The
S
3.
for
17